Women who gain weight throughout adulthood are at higher risk for developing breast cancer after menopause and women who lose weight may decrease their risk. Fifty percent of the Black female population is obese and overall breast cancer mortality for Black women is higher compared to White women. Moreover, insulin and insulin growth factor (IGF) metabolism appear to mediate the relationship of obesity with breast cancer. Thus, we propose the Obesity Reduction Black Intervention Trial (ORBIT), which builds upon the findings of "Breast Cancer Risk Reduction In African-American Women" (CA88935). Results of CA88935 showed significant weight loss and improved breast health behaviors in the intervention compared to the control group. The next critical step in our research is to asses the efficacy of a weight loss/breast health intervention and maintenance intervention and the association between these and potential biomarkers of breast cancer risk. Two hundred obese 30-50 year old Black women will be randomized to a 24-week Active Intervention or a 24-week Control Intervention. Active Intervention participants will then participate in a 1-year weight loss/breast health maintenance intervention and Control participants will participate in a 1- year control maintenance intervention. The primary aims of the study are: 1) To estimate the effectiveness of a 24-week weight loss and a 1-year maintenance intervention to produce and maintain weight loss through a reduction in total calories, total fat, and an increase in fruit and vegetable consumption, as well as physical activity; and 2) To estimate the effectiveness of the 24-week and 1-year maintenance intervention on changes in fasting serum insulin, glucose, and free insulin like growth factor 1 (free IGF 1) and insulin like growth factor binding proteins (IGFBP) 1 and 2 between intervention and control women. [unreadable] [unreadable]